PackardV8 wrote:FWIW, engine dynos which simulate and repeat various track loads have been around for 40 years that I know of. Ford used full-scale dyno load runs for their mid-60s Indy development, where engines simulated the full 500 miles of acceleration, decel and pit stops. In the late 60s-early 70s Le Mans efforts each shift was simulated for the full 24 hours.

F1 actually data logs and loads each driver's track test sessions. Once a new engine parameter has been established on the dyno, it can be transfered and repeat the run virtually to see if it adds speed/subtracts time at various points on any of the tracks. Only if it shows promise is the actual full race length dyno run.

thnx, jv.

The ability of this inertia-dyno to perform simulated laps, drag race runs, etc. is a secondary function of the machine. (Secondary in design, not ability.) The main purpose of the inertia dyno is to have the ability to precisely record the engine's actual accel-rate and to repeat within 0.5%. This provides the engine specialists with the best data to evaluate components/combinations, etc. On-track simulations are continually being tested; however in most cases will be customized for each individual customer's needs.

The F-1 dyno's are very impressive, but also come with a pretty impressive price-tag. (Fully equipped are well into 7-figures!) And the F-1 dyno's are still the "absorber" type (electric) - and have their limitations. As one of the top NASCAR chief engine-builders told me - "they are not perfect and have their issues!" (Referring to the computerized, AC dyno's.)

Mike Laws
Get'm Garage
Home of the Twin Blade Series carburetors, Titan Metering Blocks, Piston Cooling System and more...

Mike refers to the "natural" acceleration rate of the engine. That is exactly right! The engine accelerates the inertia at whatever rate it can based on the inertia value and the amount of torque the engine produced while doing the accelerating. This goes back to our saying that the engine drives the dyno (much like a dog wagging a tail) rather than the dyno controlling the engine (what we call the tail wagging the dog!). Hence, inertia testing versus water brake testing, respectively.

There are many mixed opinions regarding this type of testing but the data draws the conclusion.

I know in Australia they use Dyno Dynamics which is not nearly as popular in the United States. I saw several in action while I was there.

My understanding is the V8 Super Car Teams have developed simulations of the courses they run on, and they run endurance tests on the Dyno Dynamics Dyno which actually mimic the conditions one see on the actual circuit. They can then run either the engine, or the entire car through an actual race.

The Dyno Dynamics software runs on both a water brake engine dyno along with an Eddy Current Chassis dyno. The nice things from a late model engine is it integrates OBDII input so you can correlate your data directly from the PCM to the Dyno output.

It may not be as cool as this new dyno, but it does allow for some fairly detailed tuning to be done.

Are you guys measuring cylinder pressures on the dyno to equalize cylinder to cylinder power output as well?

No we're not; however a dyno-customer is about to begin a series of extensive development tests and I understand that cylinder pressure measurement is on their list of to-do's.

Accurate measurement of CPM is one of the most sought after develoment areas and I hope to see the results of this testing. I am unsure about the quality of CPM sensors at this time as I've heard conflicting stories. I know that Ford (and probably GM, Dodge, Toyota, etc.) have spent a lot of time & $$ on CPM, but I do not have any first hand experience.

ML

Mike Laws
Get'm Garage
Home of the Twin Blade Series carburetors, Titan Metering Blocks, Piston Cooling System and more...

Are you guys measuring cylinder pressures on the dyno to equalize cylinder to cylinder power output as well?

No we're not; however a dyno-customer is about to begin a series of extensive development tests and I understand that cylinder pressure measurement is on their list of to-do's.

Accurate measurement of CPM is one of the most sought after develoment areas and I hope to see the results of this testing. I am unsure about the quality of CPM sensors at this time as I've heard conflicting stories. I know that Ford (and probably GM, Dodge, Toyota, etc.) have spent a lot of time & $$ on CPM, but I do not have any first hand experience.

ML

Thanks, There are actually a number of companies working on CPM stuff right now that is getting close to affordable for testing that seems to be pretty accurate. Sort of like the WBO2 deal I know when we first were getting into them it's over G a cylinder, and now it's a lot more reasonable.

Doug Schriefer

Braswell Carburetion
(520) 908-7781

Check us out on FaceBook:
http://www.facebook.com/pages/Braswell-Carburetion/320755068324

Dave Koehler wrote:Thread back from the dead.
The inertia dyno subject came up again today at lunch and once in a while I ponder building one. So I went looking again.

Revolution must have gone belly up.

Anyone else offering an engine inertia dyno?

Anyone built one?

I know of two inertia dynos built by a guy in Canada and for the life of me, I can't think of his name right now. I know one is outside Portland Oregon. Can't think of where the second one is...but my memory says the second one that I know of was owned by Walt Austin.

I would think that you should try and get in touch with Mike Laws. I can say that a number of years ago when I was looking to match their HP calculations from some of the measured data Mike was very helpful and more than willing to share information.

Stan

Stan Weiss / World Wide Enterprises
Offering Performance Software Since 1987
Do you use engine simulation software that uses cylinder head flow files?
We have a package of more than 3000 DFW or FLW Files

Yup,
Les davenport is who you are probably thinking about.
Several of the big boys have one. Mandoline might have been the earliest adapters. Rage, DMPE and others also use them on blown engines.
Never personally stood next to one to soak in the parts needed so taking another look around.

Dave Koehler wrote:Yup,
Les davenport is who you are probably thinking about.
Several of the big boys have one. Mandoline might have been the earliest adapters. Rage, DMPE and others also use them on blown engines.
Never personally stood next to one to soak in the parts needed so taking another look around.

There are lots of companies that make very VERY advanced dynos. Except they don't call them that, they call them "Test Cells". Your imagination is the limit, but your pocketbook is your reality.

SwRI and Wineman Technologies are two that pop to mind immediately, only because I've personally worked with them both.

FWIW, I can see the allure to an inertia dyno, especially if it was run through a true drivetrain. Sure you could convince yourself you could simulate that with just a brake, but reality requires no convincing.

Hey guys,
This is Kevin Finney. I saw the activity on the post and I can chime in. I was the project engineer at Excelleration, LLC when we were developing the Revolution Inertia Dyno from 2005-2010. This is the machine that Mike Laws was involved with.

We couldn't survive the dismal economic conditions that were happening in the Motorsports world, and other dyno companies like AVL were entering the NASCAR engine shops with their AC electric motoring dynos.

We stopped operating as a daily business in May of 2010. However, we still service and maintain the machines we sold/leased.

I have been working at Gray Motorsports in Denver, NC since 2013 after a couple year stint at Chip Ganassi Racing.

This idea is realistically a mind exercise at the moment as I do not have the finances to buy more land and expand. I just don't have the room.
ButBUT
I was looking at my digger one day.
I see an engine, clutch, 2 speed lenco trans, rear end and chassis and go hmmmm.
I have 90% of the hardware in front of me.
I consider making something to clamp the chassis to the floor and manufacture two units with the flywheels that could attach to the axle hubs via shorty driveshafts.
All covered with appropriate shielding.
Then add some suitable sensors and software.

That is certainly more doable for me unless someone can point out the weaknesses in it.
Please Add to the idea or pick it apart.